A 0.5-V sub-μW/channel neural recording IC with delta-modulation-based spike detection

A neural recording IC with a new spike detection scheme is proposed to minimize power dissipation while preserving the waveform information of the detected spikes. A delta modulator is employed in the recording IC to reduce signal dynamic range and enable low-voltage operation. A series of output values from the delta modulator are stored in a small amount of analog memory to extract two key features of the neural signal - amplitude and frequency, which are used for accurate spike detection. Using the stored delta values, the precise spike waveform information can be conserved. A prototype recording IC with 16 channels has been fabricated using 0.18-μm CMOS technology. Measurement results demonstrate the spike detection capability successfully. The fabricated IC consumes only 0.88 μW/channel at 0.5-V supply.